Chicago – Reality hit the Vikings on Sunday like winter's first shiver.

Facing a dysfunctional team reeling from a pair of historic losses, needing a victory to reach .500 and dip a toe into the waters of contention, the Vikings for the second straight season earned a season-defining loss at Soldier Field, falling 21-13 to the Bears.

In 2013, the defense gave up a game-losing touchdown in the final seconds, then sulked in the locker room about the confusion caused by its defensive coordinator. That was a team with playoff aspirations dashed by mismanagement. "Honestly, that one probably hurt more,'' veteran linebacker Chad Greenway said.

That the 2014 team would contend for the playoffs without Adrian Peterson or its chosen starting quarterback was a fanciful conceit disproved by a cold afternoon in a lakeside sandbox.

Vikings coach Mike Zimmer used a barnyard epithet to describe Soldier Field's malfunctioning game clocks, but it was his offense that stood still, turning a 10-0 lead into another wasted trip to what for Minnesota is the Winless City.

Whatever delusions of grandeur this team had were blown away by fundamental, schematic and physical failures.

The Bears' porous defense? More than stout enough against the Vikings' tentative running game, invisible receivers and jittery rookie quarterback.

The Bears' reality-show relationships on offense? It's easy to get along when you're celebrating third-down conversions and touchdowns.

Minnesota's hopes of getting Peterson back in time to rush toward the playoffs? Irrelevant, with the Vikings at 4-6 and tied for last place in the division.

They got pushed around by a team that is anything but a powerhouse. They played like they were running in quicksand, and there might be something to that. Greenway, who has won just once in Chicago, said he wears 7-inch studs on his cleats to gain traction on the notoriously shoddy Soldier Field turf. Rookie linebacker Anthony Barr looked like he was wearing roller skates.

Zimmer, a renowned defensive coach, chose not to imitate other successful game plans against the Bears. He eschewed playing zone, leaving 5-10 cornerback Josh Robinson playing man-to-man against the Bears' hulking receivers. "I can't make these guys taller,'' Zimmer said.

He does have to hope his players will grow. The Vikings looked overwhelmed.

Teddy Bridgewater, the rookie quarterback, played his worst game since Week 6, when the Lions' stout defensive line robbed him of space and time. "He was not as good today as he has been,'' Zimmer said.

Barr, who was becoming a symbol of Zimmer's foresight, missed tackles all over the field. "I can't speak for him, but I know that this is a difficult place to keep your footing,'' Greenway said. "This is different than any other surface we play on.''

Jerick McKinnon, the promising back, didn't hit the holes hard or make tacklers miss, meaning for perhaps the first time this season, the Vikings sorely missed their star.

Peterson and the NFLPA are challenging the NFL's right to keep him on the suspended list, and the language chosen in Peterson's statement can be interpreted as an invitation to a protracted court battle.

Had the Vikings won in Chicago, they would be 5-5. They would be forced to behave like contenders, which might have meant pushing for Peterson's reinstatement.

At 4-6, the pressure is off. This team hasn't beaten an opponent who currently has more than four victories. The Vikings are 0-3 in the division. Their implosion in Chicago turned 2014, finally, into what it should have been all along — a chance to develop young players and fully install Zimmer's defense and Norv Turner's offense.

When the Vikings lost at Soldier Field in 2013, you could hear the front office typing up Leslie Frazier's pink slip.

Sunday, you could hear calendars being flipped. All of the rookies — including Zimmer, Bridgewater, Barr and McKinnon — now know what it means to wear purple in Chicago.

Next year, they'll have to wear longer cleats, stand closer to the heaters, and understand that even a bad Bears team can ruin a Vikings season.

Jim Souhan's podcast can be heard at souhanunfiltered.com. Twitter: @SouhanStrib • jsouhan@startribune.com